// Convert an RGB color value into a pixel using this colormap.
// This assumes that standard colors have already been expanded.
internal XPixel RGBToPixel(Color color)
{
try
{
// Acquire the display lock.
IntPtr display = dpy.Lock();
// Do we already have a cached pixel value for this color?
Object cached = cachedPixels[color];
if (cached != null)
{
return((XPixel)(cached));
}
// Try to allocate the color from the X display server.
XColor xcolor;
int red = color.Red;
int green = color.Green;
int blue = color.Blue;
xcolor.pixel = XPixel.Zero;
xcolor.red = (ushort)(red << 8);
xcolor.green = (ushort)(green << 8);
xcolor.blue = (ushort)(blue << 8);
xcolor.flags =
(sbyte)(XColor.DoRed | XColor.DoGreen | XColor.DoBlue);
xcolor.pad = (sbyte)0;
if (Xlib.XAllocColor(display, colormap, ref xcolor) != 0)
{
// Cache the value for next time.
cachedPixels[color] = xcolor.pixel;
return(xcolor.pixel);
}
// TODO: do a closest color match for the color.
// Last ditch: return black or white depending upon
// the intensity of the color.
if (((color.Red * 54 + color.Green * 183 +
color.Blue * 19) / 256) < 128)
{
return(Xlib.XBlackPixelOfScreen(screen.screen));
}
else
{
return(Xlib.XWhitePixelOfScreen(screen.screen));
}
}
finally
{
dpy.Unlock();
}
}
// Create a new application group for embedding a child application.
private unsafe void CreateApplicationGroup()
{
String displayName;
Xauth *auth;
Xauth *authReturn;
XSecurityAuthorizationAttributes xsa;
Xlib.XSecurityAuthorization xs;
// Check that we can create application groups.
if (!CanEmbed(dpy, true, out displayName))
{
return;
}
try
{
// Lock down the display while we do this.
IntPtr display = dpy.Lock();
// Create the application group identifier.
if (Xlib.XagCreateEmbeddedApplicationGroup
(display, XVisualID.Zero,
Xlib.XDefaultColormapOfScreen(screen.screen),
Xlib.XBlackPixelOfScreen(screen.screen),
Xlib.XWhitePixelOfScreen(screen.screen),
out group) == XStatus.Zero)
{
return;
}
// Generate an authentication token for the group.
auth = Xlib.XSecurityAllocXauth();
if (auth == null)
{
return;
}
auth->name = Marshal.StringToHGlobalAnsi
("MIT-MAGIC-COOKIE-1");
auth->name_length = 18;
xsa = new XSecurityAuthorizationAttributes();
xsa.timeout = 300;
xsa.trust_level = 0; // XSecurityClientTrusted
xsa.group = (XID)group;
xsa.event_mask = 0;
authReturn = Xlib.XSecurityGenerateAuthorization
(display, auth,
(uint)(XSecurityAttributeMask.XSecurityTimeout |
XSecurityAttributeMask.XSecurityTrustLevel |
XSecurityAttributeMask.XSecurityGroup),
ref xsa, out xs);
if (authReturn == null)
{
Xlib.XSecurityFreeXauth(auth);
return;
}
// Write the credentials to a temporary X authority file.
String authFile = Path.GetTempFileName();
FileStream stream = new FileStream
(authFile, FileMode.Create, FileAccess.Write);
WriteShort(stream, 65535); // family = FamilyWild
WriteShort(stream, 0); // address_length
WriteShort(stream, 0); // number_length
WriteShort(stream, authReturn->name_length);
WriteBytes(stream, authReturn->name,
authReturn->name_length);
WriteShort(stream, authReturn->data_length);
WriteBytes(stream, authReturn->data,
authReturn->data_length);
stream.Close();
// Free the Xauth structures that we don't need any more.
Xlib.XSecurityFreeXauth(auth);
Xlib.XSecurityFreeXauth(authReturn);
// Record the app group information.
redirectDisplay = displayName;
authorityFile = authFile;
// Create a wrapper around the appgroup to get events.
groupWrapper = new AppGroupWidget(dpy, screen, group, this);
}
catch (MissingMethodException)
{
return;
}
catch (DllNotFoundException)
{
return;
}
catch (EntryPointNotFoundException)
{
return;
}
finally
{
dpy.Unlock();
}
}
